Mercury <1.2 lbs Hg/Tbtu (except Pirkey 4.0# Hg/TBbtu) - PowerPoint PPT Presentation

1 Regulates Mercury, Metals HAPS, Acid Gases and Dioxin/Furans • Mercury • <1.2 lbs Hg/Tbtu (except Pirkey 4.0# Hg/TBbtu) • Monitored for reporting with Sorbent Traps on Fleet • Most plants will use mercury CEMS of operational indication • Acid Gases • <0.002 lbs HCl/Mbtu • Reporting across fleet: • SO 2 as a surrogate (<0.2#SO 2 /MBtu) • -or- Quarterly stack testing for HCl • Non-Mercury Metal HAPS • Quarterly stack particulate monitoring (<0.03 lbs particulate/ • Mbtu) Dioxin/Furans • Boiler inspections, repairs and tuning (CO, NO x , O 2 ) • Annual reporting required. •

2 MERCURY ACID GASES Non-Hg Metals SCR & WFGD WFGD ESP – WFGD ACI* & Fabric Filter SBC** & Fabric Filter Fabric Filter DFGS & FF ACI & NID NID NID ACI & ESP SBC & ESP ESP ACI & CaBr2 & ESP WFGD ESP - WFGD WFGD & GMCS WFGD ESP - WFGD * ACI – activated carbons are typically a halogenated variety. ** SBC – Sodium bicarbonate – dry injected into fluework.

3  Numerous options to comply – very specific based upon plant.  Utilization of existing equipment.  Combustion process and acceptable fuel options.  Unit designed are specific to a specific type/range of coal.  Halogens in fuel --- Hg oxidation, corrosion, competing FGD reactions.  Economic Drivers  Cost benefit - - capital to costly = retire units  Cost avoidance – maintain ESP for ash sales/avoid landfill expansion.  Holistic Process View (Total Evaluated Cost)  Sodium salts get to landfill and into landfill leachate.  Flyash collection in WFGD, contributes to increase arsenic in absorbers.  SCR ammonia slip affect on WFGD’s Hg removal.  ESP performance with additional particulate (AC, trona, SBC).  Equipment arrangement and space.  Utilize as much of existing equipment (ductwork, stack) in retrofits.  More remote areas increase capital and operating costs.  Schedule  Compliance date.  May limit options.

Scale

Trona, Br-AC, Absorber SBC Boiler Stack ESP Dewatering FGD WWT LANDFILL LEACHATE POND Plant Pond Complex